Schedule 8A 


August 25, 1920 


DEPARTMENT OF THE INTERIOR 

JOHN BARTON PAYNE, Secretary 

II. S, BUREAU OF MINES 

n 

FREDERICK G. COTTREEE, Director 


PROCEDURE FOR ESTABLISHING A LIST 
OF PERMISSIBLE METHANE INDICATORS 

FOR MINES 

FEES, CHARACTER OF TESTS, AND CONDITIONS 
UNDER WHICH INDICATORS 
WILL BE TESTED 



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WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1920 





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The Bureau of Mines, in carrying out one of the provisions of its organic 
act—to disseminate information concerning investigations made—prints a 
limited free edition of each of its publications. 

When this edition is exhausted, copies may be obtained at cost price only 
through the Superintendent of Documents, Government Printing Office, Wash¬ 
ington, D. C. 

The Superintendent of Documents is not an official of the Bureau of Mines. 
His is an entirely separate office and he should be addressed: 

Superintendent of Documents, 

Government Printing Office, 

Washington, D. 0. 

The general law under which publications are distributed prohibits the giving 
of more than one copy of a publication to one person. The price of this publi¬ 
cation is 5 cents. 


First edition. November , 1920. 


library of congress 

RECEIVED 

JAN 101921 

DOCUMENTS DIVISION 








PROCEDURE FOR ESTABLISHING A LIST OF PERMISSIBLE METHANE INDICATORS 
FEES, CHARACTER OF TESTS, AND CONDITIONS UNDER WHICH 
INDICATORS WILL BE TESTED. 


AUTHORIZATION. 

An act of Congress (37 Stat., G81) approved February 25, 1913, 
contains the following provision in regard to tests or investigations 
performed by the Bureau of Mines: 

That for tests or investigations authorized by the Secretary of the Interior 
under the provisions of this act, other than those performed for the Govern¬ 
ment of the United States, or State governments within the United States, a 
reasonable fee covering the necessary expenses shall be charged according to 
a schedule prepared by the Director of the Bureau of Mines and approved by 
the Secretary of the Interior, who shall prescribe rules and regulations under 
which such tests or investigations may be made. All moneys received from 
such sources shall be paid into the Treasury to the credit of miscellaneous 
receipts. 

PURPOSE. 

The object of this schedule is to establish a list of permissible 
methane indicators for use by fire bosses and other mine officials, 
which will be more accurate than flame safety lamps but probably 
not so dependable as laboratory analyses. 

The Bureau of Mines will make tests at its Pittsburgh experiment 
station to establish a list of permissible methane indicators for use in 
mines. This schedule is issued for the information and guidance of 
those who may desire to submit such devices for test. It supersedes 
Schedule 8, issued under date of December 11, 1916, and goes into 
effect on approval by the Secretary of the Interior. 

DEFINITION OF PERMISSIBLE. 

The Bureau of Mines considers a methane indicator to be per¬ 
missible for use in mines if all the details of the indicator’s con¬ 
struction are the same in all respects as those of the indicator that 
passes the inspection and the tests for safety, accuracy, and reliability 
made by the bureau and hereinafter described. 

CONDITIONS UNDER WHICH INDICATORS WILL BE TESTED. 

The conditions under which the Bureau of Mines will examine 
and test indicators to establish their permissibility are as follows: 

1. The examination and tests will be made at the experiment sta¬ 
tion of the Bureau of Mines at Pittsburgh, Pa. 

16087 °— 20 


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4 


PERMISSIBLE METHANE INDICATORS FOR MINES. 


2. Applications for tests shall be addressed to the Director, Bureau 
of Mines, Washington, D. C., and shall be accompanied by a com¬ 
plete description of the indicator to be tested, complete and detailed 
instructions for its use, and a full set of the drawings showing all the 
details of the indicator’s construction. 

A copy of the description, a copy of the instructions, a duplicate 
set of the drawings, and one complete indicator shall be sent prepaid 
to the electrical engineer, Bureau of Mines, 4800 Forbes Street, Pitts¬ 
burgh, Pa. 

3. As soon as possible after the receipt of his application for test, 
the manufacturer will be notified of the date on which his indicator 
will be tested and the amount of any additional material that it will 
be necessary for him to submit. 

4. The manufacturer shall deliver to the Bureau of Mines, 4800 
Forbes Street, Pittsburgh, Pa., two weeks prior to the date set for 
the test, the necessary material for determining the permissibility of 
his equipment. The tests will be made in the order of the receipt of 
application for test provided that the necessary material is sub¬ 
mitted at the proper time. If the necessary material has not been 
received at the date set for beginning the test, the applicant next in 
line shall have precedence. 

5. Permissibility tests of accessories for methane indicators will 
not be made unless such accessories have been completely developed 
and are in a form which can be put on the market. 

6. No one is to be present at these tests except the necessary Gov¬ 
ernment officers, their assistants, representatives of the manufacturer 
of the indicator to be tested, and such other persons as may be mu¬ 
tually agreed upon by the manufacturer and the bureau. 

T. The details of the results of the tests shall be regarded as confi¬ 
dential by all present at the tests and shall not be made public in any 
way prior to their official publication by the Bureau of Mines. 

REQUIREMENTS FOR APPROVAL. 

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The subdivisions on the indicator scale shall not indicate greater 
accuracy than can be obtained with the indicator. 

The indicators will be examined and tested with respect to safety, 
sensitiveness, and accuracy of indications and general reliability. 
The construction of permissible methane indicator equipment shall be 
especially durable. All parts shall be constructed of suitable ma¬ 
terial of the best quality and shall be assembled in a thorough, work¬ 
manlike manner. 

SAFETY. 

The indicators shall be so constructed that they can not ignite an 
explosive mixture of methane and air external to the indicator. Cur¬ 
rent-carrying parts shall be well insulated from parts of opposite 


PERMISSIBLE METHANE INDICATORS FOR MINES. 


5 


polarity and from parts not intended to carry current, and so pro¬ 
tected as to preclude the possibility of anyone’s* meddling with the 
electrical contacts or making electrical connection with them. 

ACCURACY TESTS. 

Indicators shall be capable of indicating percentage of methane up 
to and including 4 per cent in mine atmospheres having temperatures 
ranging from 50° to 70° F., and when subjected to changes in mine 
temperature, between successive determinations, of 5° F. 

Table showing permissible variations in scale reading. 


Methane 
in mix¬ 
tures, 
percent. 

Minimum 
indication 
of indicator, 
per cent. 

Maximum 
indication 
ofindicator, 
per cent. 

0.25 

0.10 

0.40 

.50 

.35 

.65 

1.00 

.80 

1.20 

2.00 

1.80 

2.20 

3.00 

2. 70 

3.30 

4.00 

3.70 

4.30 


Ten determinations shall be made for each percentage given in the 
preceding table. These determinations shall be made at different 
temperatures to prove the accuracy of detector throughout the tem¬ 
perature range (50° to 70° F.) and under conditions of sudden tem¬ 
perature changes of 5° F. 

The average result of 10 readings shall be within the limits of 
error given in the preceding table. Not more than two readings for 
each percentage shall exceed the limits of error given in this table. 

RELIABILITY. 

Indicators will be examined to determine the excellence of the 
mechanical design and construction of the device with especial refer¬ 
ence to the durability of permanent parts and to the ease of replacing 
properly such parts as have an admittedly limited life. 

The average number of indications which an indicator shall be cap¬ 
able of determining without recharging the battery or replacing any 
parts shall be 15. This average number shall be determined by not 
less than 10 trials. 

Four indicators completely assembled shall each be dropped 20 
times on a wooden floor from a height of 3 feet. The indicator shall 
be held in normal position when dropped and the dropping distance 
shall be determined as that from the bottom of the indicator to the 
floor. 

The average number of times that indicators can be dropped before 
breaking glasses or glowers, or before material distortion of any other 
parts of the indicator, shall not be less than 10. 








6 


PERMISSIBLE METHANE INDICATORS FOR MINES. 


If an indicator does not meet these requirements owing to a failure 
of glass, glower, or other similar renewable part, the manufacturer 
shall have the right to submit a new design of such renewable part 
for retest, for which test a reasonable fee shall be charged. 

INDICATORS WITH LIGHTING ATTACHMENTS. 

If indicators are provided with lighting attachments, such attach¬ 
ments shall be subject to the same tests for safety, practicability, and 
efficiency as those made for portable electric miners 1 lamps. For 
details of test procedure see Schedule 6A. 1 

REQUIREMENTS FOR BATTERIES. 

Batteries used with indicators shall have short-circuit currents 
not in excess of the following values: For batteries giving 2.5 volts 
or less, 125 amperes; for batteries giving more than 2.5 volts but 
not more than 4 volts, 85 amperes; for batteries giving more than 
4 volts but not more than 5 volts, 65 amperes; for batteries giving 
more than 5 volts but not more than 6 A r olts, 45 amperes. Therefore, 
a battery whose short-circuit current does not exceed these values 
will be considered satisfactory in this respect. 

Batteries must also comply with the following requirements for 
mechanical and electrical construction: 

The construction of the battery shall be especially durable. All 
parts shall be constructed of suitable material of the best quality 
and shall be assembled in a thorough, workmanlike manner. Cur¬ 
rent-carrying parts shall be well insulated from parts of opposite 
polarity and from parts not intended to carry current. 

The battery shall be inclosed in a locked or sealed box, so con¬ 
structed as to preclude the possibility of anyone's meddling with 
the electrical contacts or making an electrical connection with them 
with the box cover closed. 

The leads from the battery to the indicator shall be made up in 
a single cable efficiently insulated and provided where it leaves 
the battery casing and where it enters the indicator with a reinforce¬ 
ment of flexible metallic tubing. The flexible metallic tubing will 
not be required if other equally durable means of reinforcement are 
provided. 

The battery terminals and leads connecting thereto and the gas 
vent of the battery shall be so designed and constructed as to prevent 
corrosion of the battery terminals or of the essential parts mounted 
in the cover of the battery casing. 


1 Procedure for establishing a list of permissible portable electric mine 
GA, 1920. 


lamps: Schell. 





PERMISSIBLE METHANE INDICATORS FOR MINES. 7 

The battery must be so designed and constructed that it will not 
spill or leak electrolyte throughout an eight-hour test, during which 
it will be placed in any position or sequence of positions that in the 
opinion of the bureau’s engineers will be most likely to prove whether 
or not the electrolyte can be spilled. 

APPROVAL PLATES. 

The manufacturer will be required to attach to the indicator a 
plate bearing the seal of the Bureau of Mines and inscribed as 
follows; 

Permissible Methane Indicator. 

Issued for Safety, Durability, and Efficiency 

to the-Company. 

Approval No.- 

The requirement of a separate approval plate will not be made 
where an equally satisfactory inscription can be made by stamping 
the casing. 

NOTIFICATION OF MANUFACTURER. 

As soon as the bureau’s engineers are satisfied that an indicator 
is permissible the manufacturer of the indicator and the mine in¬ 
spection departments of the several States shall be notified to that 
effect. As soon as a manufacturer receives formal notification that 
his indicator has passed the tests prescribed by the bureau he shall 
be free to advertise such methane indicators as permissible. 

SCOPE OF APPROVAL. 

The bureau’s approval of any indicator shall be construed as 
applying to all indicators made by the same manufacturer that have 
the same construction in the details considered by the bureau, but 
to no other indicators. 

A manufacturer, before claiming the bureau’s approval for any 
modification of any approved indicator, shall submit to the bureau 
drawings that shall show the extent and nature of such modifica¬ 
tions, in order that the bureau may decide whether the remodeled 
indicator should be tested before it is approved. 

WITHDRAWAL OF APPROVAL. 

The bureau reserves the right to rescind, for cause, at any time 
any approval granted under the conditions herein set forth. 

FEES FOR TESTING METHANE INDICATORS. 

The following fees, to be charged on and after the date of approval 
of this schedule, have been established and approved by the Secre¬ 
tary of the Interior. 




8 


PERMISSIBLE METHANE INDICATORS FOR MINES. 


ITEM 1. COMPLETE TEST. 


For a complete official investigation of a methane indicator, including 


inspection and tests of the indicator, together with a lighting attach¬ 
ment_$250 

ITEM 2. COMPLETE TEST, WITHOUT LIGHTING ATTACHMENT. 

For a complete official investigation of a methane indicator, including 
inspection and tests of the indicator_$150 

ITEM 3. SEGREGATED CHARGES. 


Indicator. 

Preliminary examination_ $5 

Safety tests_ 20 

Tests to determine accuracy of indicators_ 40 

Discharge-voltage test- 20 

Spill test_ 5 

Short-circuit test on battery_ 5 

Dropping test_ 10 

Test to determine life of parts subject to deterioration through operation— 40 

Final inspection_ 5 


Lighting Attachment. 


Safety tests_ 

Time of burning tests_ 

Light-distribution tests_ 

Mechanical tests of cord 

Bulb-life tests_ 

Bulb-uniformity tests_ 


ITEM 4. SPECIAL TESTS. 


20 

5 

20 

20 

25 

10 


250 


Special tests to assist the manufacturer in the development of 
equipment will be made at his request and will be charged for in 
accordance with the work involved. Each request for special tests 
should be accompanied by a fee of $100, made payable to the Secre¬ 
tary of the Interior. Any unused moneys from such deposits will 
be refunded at the completion of the special tests on request by the 
manufacturer. 

REMITTANCES. 


Manufacturers who submit indicators for tests to determine their 
permissibility will be required to furnish certified check or bank 
draft, made payable to the Secretary of the Interior, to cover the 
total fees required for the desired tests. Such fees must be received 
at least two weeks prior to the date set for beginning the tests; other¬ 
wise the equipment of the next applicant upon the list will be tested. 




























PERMISSIBLE METHANE INDICATORS FOR MINES. 


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SYNOPSIS OF PROCEDURE TO BE FOLLOWED IN MAKING APPLI¬ 
CATION FOR TESTS, SUBMITTING MATERIAL, CONDUCTING 

TESTS, AND NOTIFYING APPLICANT OF RESULTS. 

1. Application for tests should be addressed to the Director of the 
Bureau of Mines, Washington, D. C. The application should be ac¬ 
companied by check or draft and by a complete description of the 
indicator to be tested, instructions for its use, and a set of the draw¬ 
ings described in paragraph 2, page 4. Duplicate copies of the 
application, description, instructions, and drawings should be sent 
to the electrical engineer, Bureau of Mines, 4800 Forbes Street, Pitts¬ 
burgh, Pa., accompanied by a completely equipped indicator. 

2. As soon as the application has been reviewed by the bureau’s 
engineers the applicant will be notified of the date of test and the 
number of detector parts that it will be necessary for him to submit. 

3. After receiving this notification the applicant should send the 
material required to the electrical engineer, Bureau of Mines, 4800 
Forbes Street, Pittsburgh, Pa. This material should be delivered 
not less than tw r o weeks in advance of the date set for the beginning 
of the tests. At this time the applicant should state the name and 
address of the applicant’s representative who will witness the tests. 

4. The tests will be begun on the date set and continued until the 
indicator is approved, rejected, or withdrawn. In case a unit is 
withdrawn by a manufacturer before an investigation has been com¬ 
pleted, fees will be charged in accordance with the work performed 
at the time of withdrawal. Any surplus funds over and above those 
covering the tests made will be refunded upon due notification by the 
manufacturer that no more tests are contemplated. 

5. After the bureau’s engineers have considered the results of the 
tests, a formal report of the approval or disapproval of the indicator 
will be made to the applicant in writing by the Director of the Bureau 
of Mines. No verbal report will be made, and the details of the tests 
must be regarded as confidential by all present. 

F. G. Cottrell, 

Director . 

Department of the Interior. 

Approved August 25, 1920. 

John Barton Payne, Secretary. 


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